X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fhighmem.c;h=bed8a8bfd01f2ae96a9d3a7d7a64bc512229b445;hb=a98d3984c85222aa9efc63c4f9dd3d805ce469f2;hp=55885f64af40680971cc08b01866c4b917ab4917;hpb=a19b27ce3847c3a5d4ea6b6c91b6f7154759af23;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/highmem.c b/mm/highmem.c index 55885f6..bed8a8b 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -26,16 +26,8 @@ #include #include #include -#include #include -static mempool_t *page_pool, *isa_page_pool; - -static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) -{ - return mempool_alloc_pages(gfp_mask | GFP_DMA, data); -} - /* * Virtual_count is not a pure "count". * 0 means that it is not mapped, and has not been mapped @@ -46,6 +38,26 @@ static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) */ #ifdef CONFIG_HIGHMEM +unsigned long totalhigh_pages __read_mostly; +EXPORT_SYMBOL(totalhigh_pages); + +unsigned int nr_free_highpages (void) +{ + pg_data_t *pgdat; + unsigned int pages = 0; + + for_each_online_pgdat(pgdat) { + pages += zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], + NR_FREE_PAGES); + if (zone_movable_is_highmem()) + pages += zone_page_state( + &pgdat->node_zones[ZONE_MOVABLE], + NR_FREE_PAGES); + } + + return pages; +} + static int pkmap_count[LAST_PKMAP]; static unsigned int last_pkmap_nr; static __cacheline_aligned_in_smp DEFINE_SPINLOCK(kmap_lock); @@ -54,9 +66,29 @@ pte_t * pkmap_page_table; static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait); +/* + * Most architectures have no use for kmap_high_get(), so let's abstract + * the disabling of IRQ out of the locking in that case to save on a + * potential useless overhead. + */ +#ifdef ARCH_NEEDS_KMAP_HIGH_GET +#define lock_kmap() spin_lock_irq(&kmap_lock) +#define unlock_kmap() spin_unlock_irq(&kmap_lock) +#define lock_kmap_any(flags) spin_lock_irqsave(&kmap_lock, flags) +#define unlock_kmap_any(flags) spin_unlock_irqrestore(&kmap_lock, flags) +#else +#define lock_kmap() spin_lock(&kmap_lock) +#define unlock_kmap() spin_unlock(&kmap_lock) +#define lock_kmap_any(flags) \ + do { spin_lock(&kmap_lock); (void)(flags); } while (0) +#define unlock_kmap_any(flags) \ + do { spin_unlock(&kmap_lock); (void)(flags); } while (0) +#endif + static void flush_all_zero_pkmaps(void) { int i; + int need_flush = 0; flush_cache_kmaps(); @@ -74,8 +106,7 @@ static void flush_all_zero_pkmaps(void) pkmap_count[i] = 0; /* sanity check */ - if (pte_none(pkmap_page_table[i])) - BUG(); + BUG_ON(pte_none(pkmap_page_table[i])); /* * Don't need an atomic fetch-and-clear op here; @@ -89,8 +120,20 @@ static void flush_all_zero_pkmaps(void) &pkmap_page_table[i]); set_page_address(page, NULL); + need_flush = 1; } - flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP)); + if (need_flush) + flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP)); +} + +/** + * kmap_flush_unused - flush all unused kmap mappings in order to remove stray mappings + */ +void kmap_flush_unused(void) +{ + lock_kmap(); + flush_all_zero_pkmaps(); + unlock_kmap(); } static inline unsigned long map_new_virtual(struct page *page) @@ -120,10 +163,10 @@ start: __set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&pkmap_map_wait, &wait); - spin_unlock(&kmap_lock); + unlock_kmap(); schedule(); remove_wait_queue(&pkmap_map_wait, &wait); - spin_lock(&kmap_lock); + lock_kmap(); /* Somebody else might have mapped it while we slept */ if (page_address(page)) @@ -143,39 +186,77 @@ start: return vaddr; } -void fastcall *kmap_high(struct page *page) +/** + * kmap_high - map a highmem page into memory + * @page: &struct page to map + * + * Returns the page's virtual memory address. + * + * We cannot call this from interrupts, as it may block. + */ +void *kmap_high(struct page *page) { unsigned long vaddr; /* * For highmem pages, we can't trust "virtual" until * after we have the lock. - * - * We cannot call this from interrupts, as it may block */ - spin_lock(&kmap_lock); + lock_kmap(); vaddr = (unsigned long)page_address(page); if (!vaddr) vaddr = map_new_virtual(page); pkmap_count[PKMAP_NR(vaddr)]++; - if (pkmap_count[PKMAP_NR(vaddr)] < 2) - BUG(); - spin_unlock(&kmap_lock); + BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 2); + unlock_kmap(); return (void*) vaddr; } EXPORT_SYMBOL(kmap_high); -void fastcall kunmap_high(struct page *page) +#ifdef ARCH_NEEDS_KMAP_HIGH_GET +/** + * kmap_high_get - pin a highmem page into memory + * @page: &struct page to pin + * + * Returns the page's current virtual memory address, or NULL if no mapping + * exists. If and only if a non null address is returned then a + * matching call to kunmap_high() is necessary. + * + * This can be called from any context. + */ +void *kmap_high_get(struct page *page) +{ + unsigned long vaddr, flags; + + lock_kmap_any(flags); + vaddr = (unsigned long)page_address(page); + if (vaddr) { + BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 1); + pkmap_count[PKMAP_NR(vaddr)]++; + } + unlock_kmap_any(flags); + return (void*) vaddr; +} +#endif + +/** + * kunmap_high - map a highmem page into memory + * @page: &struct page to unmap + * + * If ARCH_NEEDS_KMAP_HIGH_GET is not defined then this may be called + * only from user context. + */ +void kunmap_high(struct page *page) { unsigned long vaddr; unsigned long nr; + unsigned long flags; int need_wakeup; - spin_lock(&kmap_lock); + lock_kmap_any(flags); vaddr = (unsigned long)page_address(page); - if (!vaddr) - BUG(); + BUG_ON(!vaddr); nr = PKMAP_NR(vaddr); /* @@ -199,7 +280,7 @@ void fastcall kunmap_high(struct page *page) */ need_wakeup = waitqueue_active(&pkmap_map_wait); } - spin_unlock(&kmap_lock); + unlock_kmap_any(flags); /* do wake-up, if needed, race-free outside of the spin lock */ if (need_wakeup) @@ -207,284 +288,8 @@ void fastcall kunmap_high(struct page *page) } EXPORT_SYMBOL(kunmap_high); - -#define POOL_SIZE 64 - -static __init int init_emergency_pool(void) -{ - struct sysinfo i; - si_meminfo(&i); - si_swapinfo(&i); - - if (!i.totalhigh) - return 0; - - page_pool = mempool_create_page_pool(POOL_SIZE, 0); - if (!page_pool) - BUG(); - printk("highmem bounce pool size: %d pages\n", POOL_SIZE); - - return 0; -} - -__initcall(init_emergency_pool); - -/* - * highmem version, map in to vec - */ -static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) -{ - unsigned long flags; - unsigned char *vto; - - local_irq_save(flags); - vto = kmap_atomic(to->bv_page, KM_BOUNCE_READ); - memcpy(vto + to->bv_offset, vfrom, to->bv_len); - kunmap_atomic(vto, KM_BOUNCE_READ); - local_irq_restore(flags); -} - -#else /* CONFIG_HIGHMEM */ - -#define bounce_copy_vec(to, vfrom) \ - memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) - #endif -#define ISA_POOL_SIZE 16 - -/* - * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA - * as the max address, so check if the pool has already been created. - */ -int init_emergency_isa_pool(void) -{ - if (isa_page_pool) - return 0; - - isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, - mempool_free_pages, (void *) 0); - if (!isa_page_pool) - BUG(); - - printk("isa bounce pool size: %d pages\n", ISA_POOL_SIZE); - return 0; -} - -/* - * Simple bounce buffer support for highmem pages. Depending on the - * queue gfp mask set, *to may or may not be a highmem page. kmap it - * always, it will do the Right Thing - */ -static void copy_to_high_bio_irq(struct bio *to, struct bio *from) -{ - unsigned char *vfrom; - struct bio_vec *tovec, *fromvec; - int i; - - __bio_for_each_segment(tovec, to, i, 0) { - fromvec = from->bi_io_vec + i; - - /* - * not bounced - */ - if (tovec->bv_page == fromvec->bv_page) - continue; - - /* - * fromvec->bv_offset and fromvec->bv_len might have been - * modified by the block layer, so use the original copy, - * bounce_copy_vec already uses tovec->bv_len - */ - vfrom = page_address(fromvec->bv_page) + tovec->bv_offset; - - flush_dcache_page(tovec->bv_page); - bounce_copy_vec(tovec, vfrom); - } -} - -static void bounce_end_io(struct bio *bio, mempool_t *pool, int err) -{ - struct bio *bio_orig = bio->bi_private; - struct bio_vec *bvec, *org_vec; - int i; - - if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags)) - set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags); - - /* - * free up bounce indirect pages used - */ - __bio_for_each_segment(bvec, bio, i, 0) { - org_vec = bio_orig->bi_io_vec + i; - if (bvec->bv_page == org_vec->bv_page) - continue; - - mempool_free(bvec->bv_page, pool); - dec_page_state(nr_bounce); - } - - bio_endio(bio_orig, bio_orig->bi_size, err); - bio_put(bio); -} - -static int bounce_end_io_write(struct bio *bio, unsigned int bytes_done, int err) -{ - if (bio->bi_size) - return 1; - - bounce_end_io(bio, page_pool, err); - return 0; -} - -static int bounce_end_io_write_isa(struct bio *bio, unsigned int bytes_done, int err) -{ - if (bio->bi_size) - return 1; - - bounce_end_io(bio, isa_page_pool, err); - return 0; -} - -static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err) -{ - struct bio *bio_orig = bio->bi_private; - - if (test_bit(BIO_UPTODATE, &bio->bi_flags)) - copy_to_high_bio_irq(bio_orig, bio); - - bounce_end_io(bio, pool, err); -} - -static int bounce_end_io_read(struct bio *bio, unsigned int bytes_done, int err) -{ - if (bio->bi_size) - return 1; - - __bounce_end_io_read(bio, page_pool, err); - return 0; -} - -static int bounce_end_io_read_isa(struct bio *bio, unsigned int bytes_done, int err) -{ - if (bio->bi_size) - return 1; - - __bounce_end_io_read(bio, isa_page_pool, err); - return 0; -} - -static void __blk_queue_bounce(request_queue_t *q, struct bio **bio_orig, - mempool_t *pool) -{ - struct page *page; - struct bio *bio = NULL; - int i, rw = bio_data_dir(*bio_orig); - struct bio_vec *to, *from; - - bio_for_each_segment(from, *bio_orig, i) { - page = from->bv_page; - - /* - * is destination page below bounce pfn? - */ - if (page_to_pfn(page) < q->bounce_pfn) - continue; - - /* - * irk, bounce it - */ - if (!bio) - bio = bio_alloc(GFP_NOIO, (*bio_orig)->bi_vcnt); - - to = bio->bi_io_vec + i; - - to->bv_page = mempool_alloc(pool, q->bounce_gfp); - to->bv_len = from->bv_len; - to->bv_offset = from->bv_offset; - inc_page_state(nr_bounce); - - if (rw == WRITE) { - char *vto, *vfrom; - - flush_dcache_page(from->bv_page); - vto = page_address(to->bv_page) + to->bv_offset; - vfrom = kmap(from->bv_page) + from->bv_offset; - memcpy(vto, vfrom, to->bv_len); - kunmap(from->bv_page); - } - } - - /* - * no pages bounced - */ - if (!bio) - return; - - /* - * at least one page was bounced, fill in possible non-highmem - * pages - */ - __bio_for_each_segment(from, *bio_orig, i, 0) { - to = bio_iovec_idx(bio, i); - if (!to->bv_page) { - to->bv_page = from->bv_page; - to->bv_len = from->bv_len; - to->bv_offset = from->bv_offset; - } - } - - bio->bi_bdev = (*bio_orig)->bi_bdev; - bio->bi_flags |= (1 << BIO_BOUNCED); - bio->bi_sector = (*bio_orig)->bi_sector; - bio->bi_rw = (*bio_orig)->bi_rw; - - bio->bi_vcnt = (*bio_orig)->bi_vcnt; - bio->bi_idx = (*bio_orig)->bi_idx; - bio->bi_size = (*bio_orig)->bi_size; - - if (pool == page_pool) { - bio->bi_end_io = bounce_end_io_write; - if (rw == READ) - bio->bi_end_io = bounce_end_io_read; - } else { - bio->bi_end_io = bounce_end_io_write_isa; - if (rw == READ) - bio->bi_end_io = bounce_end_io_read_isa; - } - - bio->bi_private = *bio_orig; - *bio_orig = bio; -} - -void blk_queue_bounce(request_queue_t *q, struct bio **bio_orig) -{ - mempool_t *pool; - - /* - * for non-isa bounce case, just check if the bounce pfn is equal - * to or bigger than the highest pfn in the system -- in that case, - * don't waste time iterating over bio segments - */ - if (!(q->bounce_gfp & GFP_DMA)) { - if (q->bounce_pfn >= blk_max_pfn) - return; - pool = page_pool; - } else { - BUG_ON(!isa_page_pool); - pool = isa_page_pool; - } - - blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE); - - /* - * slow path - */ - __blk_queue_bounce(q, bio_orig, pool); -} - -EXPORT_SYMBOL(blk_queue_bounce); - #if defined(HASHED_PAGE_VIRTUAL) #define PA_HASH_ORDER 7 @@ -517,6 +322,12 @@ static struct page_address_slot *page_slot(struct page *page) return &page_address_htable[hash_ptr(page, PA_HASH_ORDER)]; } +/** + * page_address - get the mapped virtual address of a page + * @page: &struct page to get the virtual address of + * + * Returns the page's virtual address. + */ void *page_address(struct page *page) { unsigned long flags; @@ -546,6 +357,11 @@ done: EXPORT_SYMBOL(page_address); +/** + * set_page_address - set a page's virtual address + * @page: &struct page to set + * @virtual: virtual address to use + */ void set_page_address(struct page *page, void *virtual) { unsigned long flags; @@ -605,3 +421,55 @@ void __init page_address_init(void) } #endif /* defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL) */ + +#if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT) + +void debug_kmap_atomic(enum km_type type) +{ + static int warn_count = 10; + + if (unlikely(warn_count < 0)) + return; + + if (unlikely(in_interrupt())) { + if (in_nmi()) { + if (type != KM_NMI && type != KM_NMI_PTE) { + WARN_ON(1); + warn_count--; + } + } else if (in_irq()) { + if (type != KM_IRQ0 && type != KM_IRQ1 && + type != KM_BIO_SRC_IRQ && type != KM_BIO_DST_IRQ && + type != KM_BOUNCE_READ && type != KM_IRQ_PTE) { + WARN_ON(1); + warn_count--; + } + } else if (!irqs_disabled()) { /* softirq */ + if (type != KM_IRQ0 && type != KM_IRQ1 && + type != KM_SOFTIRQ0 && type != KM_SOFTIRQ1 && + type != KM_SKB_SUNRPC_DATA && + type != KM_SKB_DATA_SOFTIRQ && + type != KM_BOUNCE_READ) { + WARN_ON(1); + warn_count--; + } + } + } + + if (type == KM_IRQ0 || type == KM_IRQ1 || type == KM_BOUNCE_READ || + type == KM_BIO_SRC_IRQ || type == KM_BIO_DST_IRQ || + type == KM_IRQ_PTE || type == KM_NMI || + type == KM_NMI_PTE ) { + if (!irqs_disabled()) { + WARN_ON(1); + warn_count--; + } + } else if (type == KM_SOFTIRQ0 || type == KM_SOFTIRQ1) { + if (irq_count() == 0 && !irqs_disabled()) { + WARN_ON(1); + warn_count--; + } + } +} + +#endif